Rare Synchronous Fireflies Discovered On Grandfather Mountain

GRANDFATHER MOUNTAIN, N.C. — A type of firefly that can light up the sky by flashing in unison has been found at Grandfather Mountain in North Carolina.

Dr. Clyde Sorenson, an entomologist from NC State University, said he discovered the flashing fireflies after staying in the state park’s guest cottage following a workshop on the mountain.

“As it got dark, the numbers steadily went up, and between 10 and 10:30 p.m., there were several hundred all around the guest cottage and Woods Walk, flashing synchronously,” Sorenson said in a blogpost on the park’s website.

The Photinus carolinus is the only species of firefly in North America that can synchronize their light patterns as part of their annual mating ritual.

A special type of firefly, the Photinus carolinus, was discovered on Grandfather Mountain. It is the only species of firefly in North America that can flash in unison. https://t.co/J4YYiItY3S

The firefly has been known to reside in the Great Smoky Mountains National Park, where they are a major attraction from May to early June.

The new discovery means the popular bugs can live at higher elevations than previously thought.

“Where they have been most widely known and recognized for so long is at Elkmont in the Great Smoky Mountains National Park. But that’s at 2,200 feet. Where I saw them [at Grandfather] was at 4,200 feet,” Sorenson said.

The fireflies are now out of season, but park staff is working to organize viewing events so the public can witness the bugs in action.

“Any time people can witness one of these really neat natural history spectacles, it increases their appreciation for the natural world and their interest in helping preserving it,” Sorenson said.